PloneRSS is a re-write of CMFFeed for Plone 2.1.1+ using ArchGenXML.

There's quite a bit of documentation knocking about at the above links, but in summary the software is designed to pull in RSS newsfeeds and store the information as items within your ZODB. It's designed to be user driven so each user can define their own newsfeeds and have the feeds displayed in a portlet(s) down the side of the screen.

Plenty of optimisation to prevent different users from dossing a server, also options for multiple servers to cooperate thus preventing multiple instances / multiple servers / multiple users behind a single IP from dossing a server. (and hence getting banned) i.e. designed to work in a hosting service environment.